Wound dressing assembly

ABSTRACT

A wound dressing assembly includes a wound cover and a carrier. The wound cover has a length and width substantially greater than a height (or thickness), a first major surface, and a second major surface, opposite the first. The first major surface has disposed thereon a wound cover pressure sensitive adhesive comprising a colloidal absorbent, and it is arranged and configured to adhere to mammalian skin during use. The carrier has a length and width substantially greater than a height (or thickness), a first major surface, and a second major surface, opposite the first. The first major surface of the carrier is disposed in facing relation and is removably attached to the second major surface of the wound cover, and it has disposed thereon at least one pressure sensitive adhesive. After application of the wound cover to skin for use, the carrier is removable from the wound cover to leave the wound cover adhered to the skin.

FIELD OF THE INVENTION

The present invention relates to wound dressings for use on the skin.More specifically, the invention is a wound dressing with a removablecomponent.

BACKGROUND OF THE INVENTION

Adhesive articles such as tapes and wound dressings and bandages arewell known in the art and are used for various medical applications forhumans and other mammals and for sports protection of humans. In thecase of wound dressing, a sterile wound covering element, such as a pad,contacts the wound, and a backing layer, or carrier, coated with apressure sensitive adhesive provides secure attachment of the dressingto bare skin adjacent to a wound.

Wound dressings such as bandages are typically constructed so that thewound-covering element and the backing layer are securely attached toone another. When the user desires to remove the dressing, such as tochange the dressing, the wound covering element and the backing layerare pulled off the user's skin simultaneously. This leaves the woundexposed and unprotected from the surrounding environment. Other times,such as for cosmetic reasons, or after an initial healing period, a usermay desire less restrictive and/or cumbersome protection may be desired.Thus, the user may desire to remove only a backing/cushioning portion,leaving the wound covering element in contact with the wound.

Alternatively, some wound dressings are very flexible or difficult tohandle without wrinkling or adhering to themselves. Thus, wound dressingapplicators made of wound dressing elements and applicator elements areused. In these cases, the dressing/applicator system is disposed on theuser's skin at the wound site. Then, the applicator element is removed,leaving the dressing at the wound site. In these systems, the bandageelements, the wound covering element and the backing layer are securelyattached to one another. Examples of such systems include Sonnenborg etal., US Patent App. No 2012/0323105, and Smith & Nephew PLC, WO PatentApp. No. 94/12134.

Other systems deliver an adhesive wound closure to the skin, but theclosure lacks absorbent capacity to take up any wound exudates. Thus,additional exudate-absorbing pads are required until seepage ends, orsuch exudates may pool between the wound and the closure. Examples ofsuch systems include:

Stenvall, U.S. Pat. No. 3,888,247, purports to disclose a first aidbandage having a flexible, adhesive-coated backing having an absorbentpad secured thereto and a strip of microporous breathable surgical tapesuperposed over the absorbent pad. Thus, upon application of the firstaid bandage the entirety of the skin-facing surface of the bandage isadhesive, and in use, a wound is covered by the adhesive layer of thesurgical tape and the surgical tape is at least partially covered by theabsorbent pad of the bandage. Finally, the flexible, adhesive-coatedbacking layer protects the entirety of the bandage. After sufficienttime has elapsed to allow for cessation of bleeding and for clotting tooccur, backing layer and pad can be removed leaving the smaller strip ofmicroporous breathable surgical tape covering the wound. This may leavea blood-stained surgical tape at the wound site.

Lee, U.S. Pat. No. 5,780,048, purports to disclose a first aid bandagedressing system incorporating a cyanoacrylate wound binding layer thatis stored in an air-tight or vacuum package prior to use. Thecyanoacrylate wound binding layer is described as occlusive and adhesivewithout the need for additional tape to hold it in place once it iscured by exposure to the moisture and oxygen in air. There is noabsorbent capacity disclosed to accommodate wound exudate, which maypool below the wound binding layer, if inadequately applied.

Lowe, US Patent Appn. No. 2008/0051688 A1, purports to disclose a twolayered wound dressing having a bottom layer pierced with a series ofapertures for adhesive attachment to the skin and a top layer has a verylow moisture vapor transmission rate to close the wound from thenenvironment and to keep moisture near the skin to promote healing. Afterinitial healing, the top layer is removed and the apertures permit anear 100% moisture vapor and oxygen transmission between the skin andthe environment. Again, there is no absorbent capacity disclosed in thissystem, and blood or other wound exudates may pool in the regions of theapertures in the bottom layer.

Each of these wound closure systems lacks absorbent capacity and mayresult in blood-stained dressings. Therefore, a need exists for a wounddressing assembly that incorporates both wound closure adhesiveproperties and sufficient exudate absorbing capacity that caneffectively protect healing wounds. In addition, the above solutionshave failed to completely solve the issue of removal of only thecarrier, leaving the wound covering element in contact with the wound,protecting the wound from the surrounding environment.

SUMMARY OF THE INVENTION

Surprisingly, we have found a novel way to provide a wound dressingassembly that incorporates both wound closure adhesive properties andsufficient exudate absorbing capacity that can effectively protectwounds as they heal.

In one aspect of the invention, a wound dressing assembly includes awound cover and a carrier. The wound cover has a length and widthsubstantially greater than a height (or thickness), a first majorsurface, and a second major surface, opposite the first. The first majorsurface has disposed thereon a wound cover pressure sensitive adhesivecomprising a colloidal absorbent, and it is arranged and configured toadhere to mammalian skin during use. The carrier has a length and widthsubstantially greater than a height (or thickness), a first majorsurface, and a second major surface, opposite the first. The first majorsurface of the carrier is disposed in facing relation and is removablyattached to the second major surface of the wound cover, and it hasdisposed thereon at least one pressure sensitive adhesive. Afterapplication of the wound cover to skin for use, the carrier is removablefrom the wound cover to leave the wound cover adhered to the skin.

In another aspect of the invention, the above wound dressing assembly isapplied to the mammalian skin and left on the skin for a desired periodof time. Subsequently, the carrier is removed from the wound cover,leaving the wound cover adhered to the mammalian skin.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of this invention will now be described in greater detail,by way of illustration only, with reference to the accompanyingdrawings, in which:

FIG. 1 is a top plan view of a first embodiment of a wound dressingassembly of the present invention;

FIG. 2 is a cross-sectional view of the wound dressing assembly of FIG.1 taken along the 2-2 plane;

FIG. 3 is a top plan view of a second embodiment of a wound dressingassembly of the present invention;

FIG. 4 is a cross-sectional view of the wound dressing assembly of FIG.3 taken along the 4-4 plane;

FIG. 5 is a top plan view of a third embodiment of a wound dressingassembly of the present invention;

FIG. 6 is a cross-sectional view of the wound dressing assembly of FIG.5 taken along the 6-6 plane;

FIG. 7 illustrates a first step of wound dressing assembly use when theassembly is first applied to the hand of a user;

FIG. 8 illustrates a second step of wound dressing assembly use when thebacking of the article is removed leaving a clear wound cover on thehand of the user; and

FIG. 9 illustrates an alternative second step of wound dressing assemblyuse when the backing of the article is removed leaving a decorated woundcover on the hand of the user.

DETAILED DESCRIPTION OF THE INVENTION

Again, wound dressings are typically constructed so that the woundcovering element and the backing layer, or carrier, are securelyattached to one another. When the dressing is removed, the woundcovering element and the backing layer are pulled off the user's skinsimultaneously, leaving the wound exposed and unprotected from thesurrounding environment. If, for cosmetic reasons or after an initialhealing period, the user desires to remove the backing layer, leavingthe wound covering element in contact with the wound, current dressingscannot be employed. Therefore, we have provided novel wound dressings inwhich the carriers are easily removable from mammalian skin leaving thewound cover on the skin.

As used herein the specification and the claims, the term “releaseliner” and variants thereof relate to a web of material that has atleast one surface arranged and configured to be removable from apressure sensitive adhesive surface in contact therewith. Generally, arelease liner is used to isolate the pressure sensitive adhesive fromthe environment to retain the surface tack thereof prior to use. Therelease liner is removed to expose the pressure sensitive adhesive foruse.

As used herein the specification and the claims, the term “releaseagent” and variants thereof relate to a coating or other surfacetreatment to enhance the removal of the surface from a pressuresensitive adhesive surface in contact therewith.

FIGS. 1 and 2 illustrate a first embodiment of a wound dressing assemblyof the present invention. The wound dressing assembly 10, which may alsobe referred to as an adhesive bandage or a sticking plaster, comprises awound cover 20 and a carrier 30.

Wound cover 20 has a length and width substantially greater than itsheight, and has a first major surface 22 and a second major surface 24opposite first major surface 22. First major surface 22 has disposedthereon a wound cover pressure sensitive adhesive 26 arranged andconfigured to adhere to mammalian skin during use.

Carrier 30 has a length and width substantially greater than its height,and has a first major surface 32 and a second major surface 34 oppositefirst major surface 32. First major surface 32 has disposed thereon atleast one pressure sensitive adhesive 38 arranged and configured toadhere to mammalian skin during use.

First major surface 22 of wound cover 20 faces the application site ofwound dressing assembly 10, while the second major surface 24 of woundcover 20 faces away from the application site. Likewise, first majorsurface 32 of carrier 30 faces the application site of wound dressingassembly 10, while the second major surface 34 of carrier 30 faces awayfrom the application site.

First major surface 32 of carrier 30 is in facing relationship andremovably attached to second major surface 24 of wound cover 20.

In some embodiments of wound dressing assembly 10, wound cover 20 andcarrier 30 are substantially coextensive. In other embodiments, such asthat illustrated in FIGS. 1 and 2, carrier 30 superposes and extendsbeyond at least a portion of wound cover 20.

Though optional, wound dressing assembly 10 may also have releaseliners, such as 42 a and 42 b in one embodiment, applied to wound coverpressure sensitive adhesive 26 and carrier pressure sensitive adhesive38. Release liners 42 a and 42 b are removed from wound dressingassembly 10 prior to application by the user.

Wound cover 20 has several functions. It serves as a barrier betweenwound cover pressure sensitive adhesive 26 and pressure sensitiveadhesive 38. Wound cover 20 also protects the wound site once, asdescribed below, carrier 30 is removed from the wound site by the user.

Wound cover 20 is thin, highly flexible or deformable, water-impervious,or substantially impervious to bodily fluids, yet breathable. In someembodiments, second major surface 24 of wound cover 20 iswater-impervious, or substantially impervious to bodily fluids. Ingeneral, the thickness of wound cover 20 is between about 80 to about300 microns (“μm”), preferably between about 100 to about 200 μm andmost preferably, about 150 μm to achieve the forming and flexingcharacteristics desired.

Preferably, the materials used in wound cover 20 are conformable to thecontours of the body, and flexible so as to permit free movement of thebody part wearing wound dressing assembly 10. Wound cover 20 is verylightweight, and may be elastic (elastomeric) in character. It can be awoven or nonwoven fabric, a film, or a foam. Preferred polymericmaterials useful in forming the wound cover 20 could include polyolefin(such as polyethylene), polyurethane, and polyvinylchloride. Otherexamples of backings include, but are not limited to, nonwoven, woven,or knitted fabrics such as cotton, polyester, polyurethane, rayon andthe like.

A polyethylene film may be used as wound cover 20. However, particularlyeffective results can be achieved with stretchable, elastomeric filmsformed of polyurethane, which has the further advantage of gas(including water vapor) transmissibility. Preferred films have aMoisture Vapor Transmission Rate (MVTR) of greater than about 300g/m²/24 h (ASTM D6701 (2001), which can be measured using a MoconPERMETRAN-W MODEL 101K testing device. It is to be understood, however,that other flexible, water insoluble polymeric films known in the artmay be used. In addition, in some applications, dissolvable films can beused. Furthermore, wound cover 20 may be formed from closed-cellpolymeric foam, particularly one with an integral skin covering the sidefacing away from the skin of the user. Foam layers formed ofpolyurethane or polyethylenes are suitable, while other polymeric foamshaving similar properties may be used. In addition, wound cover 20 maybe made from other polyolefins, vinyl polyethylene acetate, textilenon-woven fabrics, rubber, tissue paper, plastic netting, adsorbent padsor other materials known in the adhesive article art. One such materialis plastic netting sold under the trade name DELNET® (DelstarTechnologies, Middletown, Del.).

In a preferred embodiment, wound cover 20 is substantially transparent.This may be particularly desirable to protect small wounds, such asnon-bleeding cuts and the like, without visible bandages. In otherembodiments, wound cover 20 is substantially translucent. In still otherembodiments, wound cover 20 is substantially opaque. An opaque woundcover 20 can serve to hide the wound from view once carrier 30 isremoved from the user's skin. In other embodiments, such as for use inchildren's wound dressing assemblies 10, second major surface 24 ofwound cover 20 may be decorated. Decorations include color or colors,decals, printed messages, or cartoons. The decoration serves the dualpurpose of hiding the wound site from view, as well as providingentertainment for the wearer of the wound dressing assembly 10.

Again, first major surface 22 of wound cover 20 has disposed thereon awound cover pressure sensitive adhesive 26 arranged and configured toadhere to mammalian skin during use. Adhesive 26 comprises at least onecolloidal absorbent component dispersed therein. The colloidal absorbentcomponent used may be any substance that has a good performance in thisutilization. Preferred colloidal absorbent components includehydrocolloids, such as, sodium carboxymethylcellulose, pectin, xanthangum, polysaccharides, sodium or calcium alginates, chitosan, seaweedextract (carrageenan), polyaspartic acid, polyglutamic acid, hyaluronicacid or salts and derivatives thereof, among others.

Hydrocolloids, such as sodium carboxymethylcellulose and pectin, amongothers, are agents that form gels as soon as they come into contact withthe bodily fluids from the wound. When used in adhesive bandages, thesehydrocolloids are combined with elastomers and/or adhesives. Preferably,the wound cover provides a humid environment but without saturation,cicatrisation, which is a situation suitable for acceleration of thehealing.

Adhesive 26 may be any conventional adhesive known for such use, as forexample pressure acrylic adhesives, among others. Additionally, such anadhesive may contain a resin for increasing adhesion, a cohesionincreasing agent, an absorption agent (preferably a polyacrylatesuperabsorbent, a polyacrylate salt superabsorbent or a mixturethereof), a plasticizer and optionally a pigment. Adhesive 26 mayfurther be configured in discontinuous patterns, arranged in lines,screen, spray or any other which a person skilled in the art understandsas discontinuous, composed by an elastomeric base.

Again, first major surface 22 of wound cover 20 has disposed thereon awound cover pressure sensitive adhesive 26, and first major surface 32of carrier 30 has disposed thereon at least one pressure sensitiveadhesive 38. Wound cover pressure sensitive adhesive 26 has an adhesionto first major surface 22 of wound cover 20, and an adhesion tomammalian skin. The relative adhesion of the different pressuresensitive adhesives can be determined by applying to a user's skin or atest skin sample and removing the carrier from the skin/wound cover.Thus, pressure sensitive adhesive 38 disposed on the first major surface32 of carrier 30 has an adhesion to second major surface 24 of woundcover 20 that is less than the adhesion of the wound cover pressuresensitive adhesive 26 to the user's skin.

While the adhesive of the wound cover and the carrier may be the same orsimilar (with appropriate release agent treatment of the second majorsurface of the wound cover), it is preferred that the wound coverpressure sensitive adhesive is a hydrocolloid adhesive—an adhesivematrix that incorporates comprises hydrocolloids or hydrogels asdescribed above. This permits the wound cover to avoid known fibrousabsorbent structures and can be substantially transparent whileproviding sufficient absorbent capacity to accept minor levels of woundexudate.

The release agent treatment of the second major surface of the woundcover permits the easy removal of the carrier from the skin and woundcover to retain protection of the wound site while removing the carrier.One of ordinary skill in the art will recognize appropriate releaseagents, including without limitation, coatings such as silicone-based(including siloxane) coatings, polyvinyl octadecyl carbonate-basedcoatings (PVODC), and other surface treatments.

Carrier 30 may have various shapes, including but not limited to,rectangular, oval, ovoid, or oblong. The shape of wound dressingassembly 10 is defined by the shape of carrier 30. Carrier 30 may bethin, highly flexible or deformable, and may be water-impervious orsubstantially impervious to bodily fluids. In general, the thickness ofcarrier 30 is between about 50 to about 500 μm to achieve the formingand flexing characteristics desired. The carrier will be thicker (e.g.,about 200 to about 500 μm) if more substantial wound cushioning isdesired, while a thinner carrier generally will be more flexible.

It is desired for the material used in carrier 30 to be both conformableto the contours of the body, and flexible so as to permit free movementof the body part wearing the product. Further, carrier 30 could belightweight, and may be elastic (elastomeric) in character. It can be awoven or nonwoven fabric, a film or a foam. Polymeric materials usefulin forming the carrier 30 include polyolefin (such as polyethylene),polyurethane, and polyvinylchloride. Other examples of backings include,but are not limited to, nonwoven, woven, or knitted fabrics such ascotton, polyester, polyurethane, rayon and the like.

A polyethylene film may be used as carrier 30, and particularlyeffective results can be achieved with stretchable, elastomeric filmsformed of polyurethane, which has the further advantage of gas(including water vapor) transmissibility. It is to be understood,however, that other flexible, water insoluble polymeric films known inthe art may be used. Furthermore, carrier 30 may be formed fromclosed-cell polymeric foam, particularly one with an integral skincovering the side facing away from the skin of the user. Foam layersformed of polyurethane or polyethylenes are suitable, while otherpolymeric foams having similar properties may be used. In addition,carrier 30 may be made from other polyolefins, vinyl polyethyleneacetate, textile non-woven fabrics, rubber, or other materials known inthe adhesive article art. Polymers used to make carrier 30 used inbandages of the present invention may exhibit viscosity of about 500 to500,000 centipoises at temperatures of about 190° C., or about 1,000 to30,000 centipoises at temperatures of about 190° C., or about 3,000 to15,000 centipoises at temperatures of about 190° C. Carrier 30 may beimpermeable to liquid, but permeable to gas, which allows the wound andthe skin to which the elongate wound dressing assembly 10 of the presentinvention is adhered to breathe. In one embodiment, carrier 30 may havepores of such a size that will allow only the passage of gases, whichhave molecules of extremely small size. Finally, one can conceive of abacking layer that is perforated for more ventilation of the skin.Perforations may be circular in area and have a range of diameters, suchas from about 0.1 to about 0.8 millimeters. However, carrier 30 may betotally impermeable to gases, when necessary.

The dimensions of carrier 30 will depend on the proposed use of wounddressing assembly 10. Typically, small wounds use dressings which areabout 15 mm in their smallest dimension. Large wounds typically usedressings which are about 100 mm in their largest dimension.

In some embodiments, carrier 30 is substantially transparent. In otherembodiments, carrier 30 is substantially translucent. In still otherembodiments, carrier 30 is substantially opaque. In yet still otherembodiments, such as for use in children's wound dressing assemblies 10,second major surface 34 of carrier 30 may be decorated. Decorationsinclude color or colors, decals, printed messages or cartoons. Thedecoration serves the dual purpose of hiding the wound site from view,as well as providing entertainment for the wearer of wound dressingassembly 10.

First major surface 32 of carrier 30 has disposed thereon at least onepressure sensitive adhesive 38 arranged and configured to adhere tomammalian skin during use. In general, any of a variety ofpressure-sensitive adhesives can be utilized as adhesive 38. Inparticular, pressure-sensitive adhesives that are biocompatible withhuman skin are typically utilized. In some embodiments, an adhesive ofthe present invention may also be either generally water soluble orgenerally insoluble, or dispersible in an aqueous environment. Forinstance, commercially available dispersible pressure-sensitive adhesiveis sold under the trade name of HL-9415-X and is available from H.B.Fuller Company. Another suitable adhesive includes about 10-75% byweight of a polyalkyloxazoline polymer, 10-75% by weight of a functionaldiluent comprising a hydroxy compound or a carboxylic acid compound, and5-50% by weight of a tackifier.

Adhesive 38 may comprise hydrocolloids. The hydrocolloid element usedmay be any substance that has a good performance in this utilization, asfor example, sodium carboxymethylcellulose, pectin, xanthan gum,polysaccharides, sodium or calcium alginates, chitosan, seaweed extract(carrageenan), polyaspartic acid, polyglutamic acid, hyaluronic acid orsalts and derivatives thereof, among others.

Hydrocolloids, such as sodium carboxymethylcellulose and pectin, amongothers, are agents that form gels as soon as they come into contact withthe bodily fluids from the wound. When used in adhesive bandages, thesehydrocolloids are combined with elastomers and/or adhesives. Preferably,the adhesive bandage should provide a humid environment but withoutsaturation, cicatrisation, which is a situation suitable foracceleration of the healing.

Adhesive 38 may be any conventional adhesive known for such use, as forexample pressure acrylic adhesives, among others. Additionally, such anadhesive may contain a resin for increasing adhesion, a cohesionincreasing agent, an absorption agent (preferably a polyacrylatesuperabsorbent, a polyacrylate salt superabsorbent or a mixturethereof), a plasticizer and optionally a pigment. Adhesive 38 mayfurther be configured in discontinuous patterns, arranged in lines,screen, spray or any other which a person skilled in the art understandsas discontinuous, composed by an elastomeric base.

In addition, first major surface 32 of carrier 30 is in facingrelationship and removably attached to second major surface 24 of woundcover 20.

Wound dressing assembly 10 is configured so that after application ofwound cover 20 to the skin of the user, carrier 30 is removable fromwound cover 20 to leave wound cover 20 adhered to mammalian skin. Forthis to be possible, the adhesion of pressure sensitive adhesive 38 tosecond major surface 24 of wound cover 20 must be less than the adhesionof wound cover pressure sensitive adhesive 26 to both second majorsurface 24 of wound cover 20 and to mammalian skin. The result is thatcarrier 30 is capable of removal from wound cover 20 and mammalian skinwhile wound cover 20 remains adhered to mammalian skin.

FIGS. 3 and 4 illustrate a second embodiment of a wound dressingassembly of the present invention. The wound dressing assembly 110comprises a wound cover 120 and a carrier 130.

As in the embodiment of FIGS. 1 and 2, wound cover 120 has a length andwidth substantially greater than its height, and has a first majorsurface 122 and a second major surface 124 opposite first major surface122. First major surface 122 has disposed thereon a wound cover pressuresensitive adhesive 126 arranged and configured to adhere to mammalianskin during use.

Carrier 130 has a length and width substantially greater than itsheight, and has a first major surface 132 and a second major surface 134opposite first major surface 132. First major surface 132 of carrier 130has a plurality of zones, a first zone 131 which disposed thereon is afirst zone pressure sensitive adhesive 136, and a second zone 133 whichdisposed thereon is a second zone pressure sensitive adhesive 138arranged and configured to adhere to mammalian skin during use. Firstzone 131 may be coextensive with wound cover 120, but it may besubstantially coextensive with wound cover 120, or, as shown in FIGS. 3and 4, larger in area than second major surface 124 of wound cover 120.Second zone 133 at least partially surrounds first zone 131.

First major surface 122 of wound cover 120 faces the application site ofwound dressing assembly 110, while the second major surface 124 of woundcover 120 faces away from the application site. Likewise, first majorsurface 132 of carrier 130 faces the application site of wound dressingassembly 110, while the second major surface 134 of carrier 130 facesaway from the application site.

First major surface 132 of carrier 130 is in facing relationship andremovably attached to second major surface 124 of wound cover 120.

Though optional, wound dressing assembly 110 may also have releaseliners, such as 142 a and 142 b in one embodiment, applied to woundcover pressure sensitive adhesive 126, first zone pressure sensitiveadhesive 136, and second zone pressure sensitive adhesive 138. Releaseliners 142 a and 142 b are removed from wound dressing assembly 110prior to application by the user.

As with carrier 30, carrier 130 may have various shapes, may be thin,highly flexible or deformable, can be water-impervious or substantiallyimpervious to bodily fluids, and have thickness between about 0.05 to0.2 millimeter (“mm”) to achieve the forming and flexing characteristicsdesired. Other characteristics, dimensions, and materials for use incarrier 130 were described above for carrier 30.

Again, second major surface 124 of wound cover 120 is in facingrelationship and removably attached to first major surface 132 ofcarrier 130. Wound cover 120 has several functions. It serves as abarrier between wound cover pressure sensitive adhesive 126 and firstzone pressure sensitive adhesive 136. Wound cover 120 also protects thewound site once, as described below, carrier 130 is removed from thewound site by the user. Characteristics, dimensions, and materials foruse in wound cover 120 were described above for wound cover 20.

Again, first major surface 122 of wound cover 120 has disposed thereon awound cover pressure sensitive adhesive 126 arranged and configured toadhere to mammalian skin during use. First major surface 132 of carrier130 has a first zone 131 which disposed thereon is a first zone pressuresensitive adhesive 136, and a second zone 133 which disposed thereon isa second zone pressure sensitive adhesive 138 arranged and configured toadhere to mammalian skin during use. The characteristics and materialsfor use in adhesives 126, 136, and 138 were described above foradhesives 26 and 38. First zone pressure sensitive adhesive 138 may beprovided by coating the first zone 131 of the carrier 130 with suchfirst zone pressure sensitive adhesive 138, or it may be provided byadhering an intermediate layer having a first zone pressure sensitiveadhesive 138 on the surface facing the wound cover 120.

Again, first major surface 122 of wound cover 120 has disposed thereon awound cover pressure sensitive adhesive 126, and first major surface 132of carrier 130 has a first zone 131 which disposed thereon is first zonepressure sensitive adhesive 136. Wound cover pressure sensitive adhesive126 has an adhesion to first major surface 122 of wound cover 120, andan adhesion to mammalian skin. The relative adhesion of the differentpressure sensitive adhesives can be determined by applying to a user'sskin or a test skin sample and removing the carrier from the skin/woundcover. Thus, first zone pressure sensitive adhesive 136 disposed onfirst major surface 132 of carrier 130 has an adhesion to second majorsurface 124 of wound cover 120 that is less than the adhesion of thewound cover pressure sensitive adhesive 26 to the user's skin.

FIGS. 5 and 6 illustrate a third embodiment of a wound dressing assemblyof the present invention. Wound dressing assembly 210 comprises a woundcover 220, a carrier 230, and a releasable element 250.

Wound cover 220 has a length and width substantially greater than itsheight, and has a first major surface 222 and a second major surface 224opposite first major surface 222. First major surface 222 has disposedthereon a wound cover pressure sensitive adhesive 226 arranged andconfigured to adhere to mammalian skin during use. Second major surface224 has disposed thereon releasable element 250.

Carrier 230 has a length and width substantially greater than itsheight, and has a first major surface 232 and a second major surface 234opposite first major surface 232. First major surface 232 of carrier 230has disposed thereon at least one pressure sensitive adhesive 238arranged and configured to adhere to mammalian skin during use.

Releasable element 250 has a length and width substantially greater thanits height, and has a first major surface 252 and a second major surface254 opposite first major surface 252. Second major surface 254 ofreleasable element 250 has disposed thereon a first zone pressuresensitive adhesive 256. Releasable element 250 is preferably coextensivewith wound cover 220 as shown in FIGS. 5 and 6, or may be slightlysmaller than wound cover 220.

First major surface 222 of wound cover 220 faces the application site ofwound dressing assembly 210, while the second major surface 224 of woundcover 220 faces away from the application site. First major surface 252of releasable element 250 faces away from the application site, whilethe second major surface 254 of releasable element 250 faces theapplication site of wound dressing assembly 210. First major surface 232of carrier 230 faces the application site of wound dressing assembly210, while the second major surface 234 of carrier 230 faces away fromthe application site.

First major surface 232 of carrier 230 is in facing relationship andattached to first major surface 252 of releasable element 250. Secondmajor surface 254 of releasable element 250 is in facing relationshipand removably attached to second major surface 224 of wound cover 220.

Though optional, wound dressing assembly 210 may also have releaseliners, such as 242 a and 242 b in one embodiment, applied to carrierpressure sensitive adhesive 238 and wound cover pressure sensitiveadhesive 226. Release liners 242 a and 242 b are removed from wounddressing assembly 210 prior to application by the user.

As with carrier 30, carrier 230 may have various shapes, may be thin,highly flexible or deformable, can be water-impervious or substantiallyimpervious to bodily fluids, and have thickness between about 0.05 to0.2 millimeter (“mm”) to achieve the forming and flexing characteristicsdesired. Other characteristics, dimensions, and materials for use incarrier 230 were described above for carrier 30.

Again, first major surface 232 of carrier 230 is in facing relationshipand attached to first major surface 252 of releasable element 250.Releasable element 250 aids in the separation of wound cover 220 fromcarrier 230 and remains associated with the wound cover 220 after suchseparation.

Releasable element 250 may be thin, highly flexible or deformable,water-impervious, or substantially impervious to bodily fluids. Ingeneral, the thickness of wound cover 20 is as thin as possible tominimally affect the characteristics of the wound cover/releasableelement combination left on the skin to maintain the desired forming andflexing characteristics.

It is desired that the material used in releasable element 250 besimilar in behavior to the material used in wound cover 220 and carrier230. The materials must both be conformable to the contours of the body,and flexible so as to permit free movement of the body part wearingwound dressing assembly 210. Releasable element 250 could belightweight, and may be elastic (elastomeric) in character. It can be awoven or nonwoven fabric, a film, or a foam. Polymeric materials usefulin forming releasable element 250 could include polyolefin (such aspolyethylene), polyurethane, and polyvinylchloride. Other examples ofbackings include, but are not limited to, nonwoven, woven, or knittedfabrics such as cotton, polyester, polyurethane, rayon and the like.

A polyethylene film may be used as releasable element 250, andparticularly effective results can be achieved with stretchable,elastomeric films formed of polyurethane, which has the furtheradvantage of gas (including water vapor) transmissibility. It is to beunderstood, however, that other flexible, water insoluble polymericfilms known in the art may be used.

Again, second major surface 224 of wound cover 220 is in facingrelationship and removably attached to second major surface 254 ofreleasable element 250. Wound cover 220 protects the wound site once, asdescribed below, carrier 230 is removed from the wound site by the user.Characteristics, dimensions, and materials for use in wound cover 220were described above for wound cover 20.

Again, first major surface 222 of wound cover 220 has disposed thereonwound cover pressure sensitive adhesive 226 arranged and configured toadhere to mammalian skin during use. Second major surface 254 ofreleasable element 250 has disposed thereon a first zone pressuresensitive adhesive 256. First major surface 232 of carrier 230 hasdisposed thereon carrier pressure sensitive adhesive 238 arranged andconfigured to adhere to mammalian skin during use. The characteristicsand materials for use in adhesives 226, 238, and 256 were describedabove for adhesives 26 and 38.

Again, first major surface 222 of wound cover 220 has disposed thereon awound cover pressure sensitive adhesive 226, second major surface 254 ofreleasable element 250 has disposed thereon a first zone pressuresensitive adhesive 256, and first major surface 232 of carrier 230 hasdisposed thereon carrier pressure sensitive adhesive 238. Wound coverpressure sensitive adhesive 226 has an adhesion to first major surface222 of wound cover 220, and an adhesion to mammalian skin. The relativeadhesion of the different pressure sensitive adhesives can be determinedby applying to a user's skin or a test skin sample and removing thecarrier from the skin/wound cover. Thus, first zone pressure sensitiveadhesive 256 has and adhesion to second major surface 254 of releasableelement 250, and an adhesion to second major surface 224 of wound cover220. Also, carrier pressure sensitive adhesive 238 has an adhesion tofirst major surface 232 of carrier 230, and an adhesion to first majorsurface 252 of releasable element 250. The relative adhesion of theselayers can be determined as described above. Essentially, the carrier230 and its related pressure sensitive adhesive should be removable fromthe releasable element while leaving the wound cover 220 and associatedreleasable element 250 adhered to the skin.

The difference in adhesion of wound cover 220 to mammalian skin andreleasable element 250 to wound cover 220 may be achieved in a number ofways. It can be accomplished by using an adhesive with lesser adhesionin first zone pressure sensitive adhesive 256 than that used in woundcover pressure sensitive adhesive 226. Alternatively, the sameadhesives, or adhesives with the same degree of adhesion, may be used infirst zone pressure sensitive adhesive 256 and wound cover pressuresensitive adhesive 226. In these embodiments, first zone pressuresensitive adhesive 256 may be configured in discontinuous patterns onsecond major surface 254 of releasable element 250, with less adhesiveapplied on second major surface 254 of releasable element 250 than onfirst major surface 222 of wound cover 220.

Wound dressing assembly 10 is configured so that in use, the article isinitially applied by the user to the wound site such that wound cover 20is disposed on the wound. Then, after a period of time determined by theuser, carrier 30 is removed from the wound site, leaving wound cover 20remaining on the wound site. The period of time from application ofwound dressing assembly 10 to the wound site to removal of carrier 30from the wound site may be greater than about 1 hour, or greater thanabout 6 hours, or greater than about 12 hours, or greater than about 24hours, or greater than about 72 hours, for example.

FIGS. 7 to 9 are representations of methods of using the wound dressingassembly 10 of the present invention from a user's hand 60. FIG. 7 showsuser's hand 60 on which is disposed wound dressing assembly 10. FIG. 8shows wound cover 20 remaining on the user's hand 60 after removal ofcarrier 30. In this first embodiment, wound cover 20 is opaque to hidethe wound from view. FIG. 9 shows a second embodiment wound cover 20,where a cartoon 72 is printed on second major surface 24 of wound cover20. This embodiment also may hide the wound from view.

The process of manufacturing the wound dressing articles described abovemay be any of those conventionally known to produce adhesive bandages.The carrier and adhesive layers can be obtained by any methods availableat present. For example, an extrusion process may be used for obtainingthe carrier. In the same way, the adhesive layer can be made in anyknown manner. A carrier as described herein is obtained and an adhesivelayer as described herein is applied to the first surface of thecarrier. After adhesive layer is applied to the first surface of the,the wound-cover is associated with the adhesive layer, thus bonding thewound covering to the backing layer. Optionally, a release liner may beapplied to the adhesive layer. The release liner is removed from theadhesive article prior to application by the user.

The wound dressing assembly 10 described above may also be ideallysuited to deliver one or more active ingredients such as therapeutics tothe surface of the skin. When contained in the assembly 10, one or moreactive ingredients may be contained primarily or exclusively in thewound cover 20 of assembly 10. Illustrative classes of activeingredients that may be delivered to the skin via wound dressingassembly 10 of the invention include, but are not limited to,antibiotics, analgesics, antipyretics, antimicrobials, antiseptics,antiallergics, anti-acne, anesthetics, anti-inflammatories, hemostats,cosmetics, vitamins, vasodilators, emollients, pH regulators,antipruritics, counterirritants, antihistamines and steroids. Specificactive ingredients that may be delivered to the skin via the dressingsof the invention include chlorhexidine, neomycin sulfate, polymyxin-Bsulfate, zinc bacitracin, benzalkonium chloride, cetylpyridiniumchloride, bupivacaine, tetracaine, cincaine, lidocaine, benzocaine,silver sulfadiazine, hydrocortisone, metandienone, trypsin, tolazoline,heparin, pramoxine, aloe vera, tretinoin, retinol, retinaldehyde,menthol, capsaicin, alpha hydroxy acids and vitamins such as Vitamin E.

The specification and embodiments above are presented to aid in thecomplete and non-limiting understanding of the invention disclosedherein. Since many variations and embodiments of the invention can bemade without departing from its spirit and scope, the invention residesin the claims hereinafter appended.

What is claimed is:
 1. A wound dressing assembly comprising: a. a woundcover having: i. a length and width substantially greater than a height;ii. a first major surface having disposed thereon a wound cover pressuresensitive adhesive comprising a colloidal absorbent and being arrangedand configured to adhere to mammalian skin during use; and iii. a secondmajor surface, opposite the first major surface; and b. a carrierhaving: i. a length and width substantially greater than a height; ii. afirst major surface in facing relation and removably attached to thesecond major surface of the wound cover, the first major surface of thecarrier having disposed thereon at least one pressure sensitiveadhesive; and iii. a second major surface, opposite the first majorsurface of the carrier, wherein, after application of the wound cover toskin for use, the carrier is removable from the wound cover to leave thewound cover adhered to the skin.
 2. The wound dressing assembly of claim1 wherein the wound cover and the carrier are substantially coextensive.3. The wound dressing assembly of claim 1 wherein the carrier superposesand extends beyond at least a portion of the wound cover.
 4. The wounddressing assembly of claim 3 wherein the first major surface of thecarrier has a plurality of zones, a first zone coextensive with thewound cover, and a second zone, at least partially surrounding the firstzone and having disposed thereon a second zone pressure sensitiveadhesive.
 5. The wound dressing assembly of claim 4 wherein the firstzone has a first zone pressure sensitive adhesive disposed thereon andwherein the first zone pressure sensitive adhesive has an adhesion tothe wound cover that is less than that of the wound cover pressuresensitive adhesive to mammalian skin, whereby the carrier is capable ofremoval from the wound cover and mammalian skin while the wound coverremains adhered to mammalian skin during use.
 6. The wound dressingassembly of claim 4 wherein the carrier has disposed thereon a carrierpressure sensitive adhesive and a releasable element is disposed on thecarrier pressure sensitive adhesive in the first zone, the releasableelement comprising a first major surface adhered to the carrier pressuresensitive adhesive and a second major surface opposite having a firstzone pressure sensitive adhesive disposed thereon and wherein the firstzone pressure sensitive adhesive has an adhesion to the wound cover thatis less than that of the wound cover pressure sensitive adhesive tomammalian skin, whereby the carrier is capable of removal from the woundcover and mammalian skin while the wound cover remains adhered tomammalian skin during use.
 7. The wound dressing assembly of claim 4wherein the second zone has a second zone pressure sensitive adhesive isdisposed thereon for adhesion to the mammalian skin.
 8. The wounddressing assembly of claim 1 wherein the carrier has disposed thereon acarrier pressure sensitive adhesive and the second major surface of thewound cover comprises a release agent to enhance the separation of thecarrier pressure sensitive adhesive therefrom.
 9. The wound dressingassembly of claim 1 wherein the second major surface of the wound coveris substantially impervious to bodily fluids.
 10. The wound dressingassembly of claim 1 wherein the carrier is substantially transparent.11. The wound dressing assembly of claim 1 wherein the carrier issubstantially translucent.
 12. The wound dressing assembly of claim 1wherein the carrier is substantially opaque.
 13. The wound dressingassembly of any of claims 10 through 12 wherein the second major surfaceof the wound cover is decorated.
 14. The wound dressing assembly ofclaim 1 wherein the wound cover is substantially transparent.
 15. Thewound dressing assembly of claim 1 wherein the wound cover issubstantially translucent.
 16. The wound dressing assembly of claim 1wherein the wound cover is substantially opaque.
 17. The wound dressingassembly of claim 16 wherein the second major surface of the wound coveris decorated.
 18. A method of applying a wound dressing to mammalianskin comprising the steps of: a. applying to the mammalian skin a wounddressing assembly comprising: i. a wound cover having: A. a length andwidth substantially greater than a height; B. a first major surfacehaving disposed thereon a wound cover pressure sensitive adhesivecomprising a colloidal absorbent and being arranged and configured toadhere to mammalian skin during use; and C. a second major surface,opposite the first major surface; and ii. a carrier having: A. a lengthand width substantially greater than a height; B. a first major surfacein facing relation and removably adhered to the second major surface ofthe wound cover, the first major surface of the carrier having disposedthereon a carrier pressure sensitive adhesive capable of adhesion to auser's skin; and C. a second major surface, opposite the first majorsurface of the carrier; wherein the wound cover adheres to the mammalianskin; and b. removing the carrier from the wound cover, leaving thewound cover adhered to the mammalian skin.
 19. The method of claim 18,wherein the carrier is removed from the wound cover after a period ofgreater than about 1 hour.
 20. The method of claim 18 wherein thecarrier is removed from the wound cover after a period of greater thanabout 6 hours.